1. Technical Field
The present invention relates to a magnetic element which can generate and erase a skyrmion, a skyrmion memory using the magnetic element, a skyrmion memory embedded solid-state electronic device, a data-storage device embedded with a skyrmion memory, a data processing device embedded with a skyrmion memory, and a communication device embedded with a skyrmion memory.
2. Related Art
A magnetic element has been known which utilizes magnetic moment of a magnet as digital information. The magnetic element has a nanoscale magnetic structure which functions as an element of a non-volatile memory which needs no electrical power during storage of information. As the magnetic element has an advantage of ultra high density and the like due to the nanoscale magnetic structure, it is expected to have an application as mass storage medium of information and the importance has been increased as a memory device of an electronic device.
As a possible candidate for a magnetic memory device of a new generation, a magnetic shift register has been proposed by IBM in the U.S. and other entities. A magnetic shift register drives a magnetic domain wall, transfers the magnetic moment arrangement via currents, and reads stored information (see Patent Document 1).
FIG. 46 is a schematic view illustrating the principle of driving a magnetic domain wall by currents. The boundary of magnetic regions at which orientations of magnetic moments are opposing to each other is the magnetic domain wall. In FIG. 46, the magnetic domain wall in a magnetic shift register 1 is shown by solid lines. By having currents flow in the magnetic shift register 1 in a direction of arrows, the magnetic domain wall is driven. Movement of the magnetic domain wall causes a magnetic change due to an orientation of the magnetic moment positioned above a magnetic sensor 2. The magnetic change is detected by the magnetic sensor 2 and magnetic information is drawn out.
However, such a magnetic shift register 1 needs large currents when moving the magnetic domain wall, and also has a disadvantage of a low transfer speed of the magnetic domain wall. As a result, the time to write to and erase from a memory is elongated.
Thus, the present inventors proposed a skyrmion magnetic element which uses a skyrmion generated in a magnet as a unit of storage (see Patent Document 2). In this proposal, the present inventors proved that a skyrmion could be driven by currents.